Synchronizer clutch assemblies for manual transmissions typically include an intermediate torque transfer shaft situated between a torque input shaft and a torque output shaft. Located in parallel disposition with respect to the intermediate shaft is a cluster gear assembly. Torque delivery gears of different pitch diameters are positioned adjacent the intermediate shaft, and a synchronizer clutch assembly is disposed adjacent one of the gears or between two adjacent gears. The synchronizer clutch assembly functions to drivably connect the torque delivery gears for rotation and unison or to connect one or both of the gears selectively to the intermediate shaft. The synchronizer clutch assembly synchronizes rotary motion of the gears, one with respect to the other, or rotary motion of one or both of the gears selectively with respect to the intermediate shaft prior to the establishment of a driving connection between the rotary members.
Synchronizer clutch assemblies for manual transmissions are shown, for example, in U.S. Pat. Nos. 2,221,900 and 3,366,208. In the '900 patent, a synchronizer clutch hub is splined to the intermediate shaft at a location between two gears of different pitch diameter. A clutch sleeve with internal clutch teeth is mounted for axially sliding movement on the synchronizer hub. The gear to be synchronized with respect to the shaft carries external clutch teeth as well as an external clutch surface. A synchronizer clutch blocker ring is disposed between the sleeve and external clutch teeth to the gear. The blocker ring is formed with an internal cone surface adapted to engage the external cone surface of the gear.
Various spring members are known which are secured to or in cooperative engagement with the blocker ring and engageable by the clutch sleeve as the sleeve is moved toward the gear to be synchronized. As the spring elements are compressed, a blocker ring cone clutch engaging force is created which energizes the friction cone clutch and causes the synchronizer blocker ring to index annularly relative to the synchronizer hub. Spring members which are secured to or operatively interconnected with the blocker ring are shown, for example, in co-pending U.S. patent application Ser. No. 08/278,860, filed on Jul. 26, 1994, and assigned to the same. Assignee as the present invention. Other spring members for synchronized transmission are shown, for example, in U.S. Pat. Nos. 3,700,083, 4,660,707 and 4,828,087.